Simplified means and method for simultaneously controlling the voltage and current in an x-ray tube



y 1934- M. MORRISON 1,965,249

SIMPLIFIED MEANS AND METHOD FOR SIMULTANEOUSLY CONTROLLING THE VOLTAGE AND CURRENT IN AN X-RAY TUBE Filed Dec. 17, 1950 s Sheets-Sheet .1

' 25 /17 AS I W W-Z0 W Z7 ZZ/7ZZ 07? MON 77'' 0R1) MORRISON ATTORNEY July 3, 1934. M MORRISON 1,965,249

SIMPLIFIED MEANS AND METHOD FOR SIMULTANEOUSLY CONTROLLING THE VOLTAGE AND CURRENT IN AN X-RAY TUBE Filed Dec. 17, 1930 3 Sheets-Sheet 2 MON TF 0RD MORE/SON B Y R w) E 7 A; &

AT'FOPNEY July 3, 1934. M, MORRISON 1,965,249

SIMPLIFIED MEANS AND METHOD FOR SIMULTANEOUSLY CONTROLLING THE VOLTAGE AND CURRENT IN AN X-RAY TUBE Filed Dec. 17, 1930 5 Sheets-Sheet 3 o i 1 5 m 36 c ,1 i i 1111K 36 Zizz/e7zf0z MONTF'ORD MORRISO A T'TORNEY iatented July 3, 1934 UNITED STATES SIMPLIFIED MEANS SIMULTANEOUSLY AND METHOD FOR CONTROLLING THE VOLTAGE AND CURRENT 1N AN X-RAY TUBE Mcntford Morrison, Montclair, N. J., assignor to Westinghouse X-R-ay ration of Delaware Company, Inc., a corpo- Application December 17, 1930, Serial No. 502,907

13 Claims.

My invention relates to X-ray devices and has particular relation to a simplified structure for simultaneously regulating the voltage and current supplied to an X-ray tube.

X-ray tubes as now employed in the art are usually constructed in such a manner that they may readily be adapted for various purposes each of which imposes an entirely different condition upon the X-ray tube. While employing an X-ray tube for one purpose it occasionally becomes highly desirable to convert the apparatus and thus adapt the tube for a different purpose with the greatest possible rapidity.

As example, the most common occasion for immediate conversion arises during a fluoroscopic examination of the human anatomy wherein the diagnostician observes some peculiar phenomenon of a particular organ and desires to take a radiographie exposure before the organ in its natural function alters its position. In the making of a fluoroscopic examination of the human anatomy a relatively higher current and a lower voltage is impressed upon the X-ray tube than in the taking of a radiographic exposure I wherein the converse condition is normally imposed upon the X-ray tube.

Apparatus as now employed in the art require the changing of numerous controls and lovers to convert the apparatus in order to impress the desired current and voltage conditions upon the X-ray tube. This requirement necessarily consumes much time when a fraction of a minute may means success or failure of the radiographic exposure before movement of the organ. The operator in manipulating these numerous controls and levers with great rapidity is very apt to make an erroneous movement resulting in irreparable damage to the apparatus and injury to the patient.

It is accordingly an object of my invention to provide a simplified apparatus which may be readily converted from one adaptation to another by the actuation of a single control to thereby vary the voltage and current supplied to an X-ray tube.

Another object of my invention is the provision of an apparatus in which a constant potential is maintained between the electrodes of an X-ray tube while the discharge current is varied.

A further object of my invention is the provision of an apparatus in which a constant discharge current is maintained in an X-ray tube while the potential between the electrodes is varied.

Still further objects of my invention will become apparent to those skilled in the art by ref erence to the accompanying drawings wherein;

Fig. 1 is a diagrammatical view of one embodiment of my invention;

Fig. 2 is a diagrammatical view showing a modification of my device;

Fig. 3 is a side view partly in cross-section of the structure of my device utilized with the circuit shown in Fig. 2 and Fig. t is a detailed View of the control handle shown in Fig. 3.

Referring now to the several figures I have shown in Fig. 1 an auto-transformer 1 arranged to receive electrical energy from any suitable source, such as an alternating current generator G, through supply conductors L1 and L2. A suitable switch S'W is provided in the supply conductor L2 for the purpose of opening and closing the supply circuit to the auto-transformer.

A pair of tension transformers 2 and 3 are provided for energizing an X-ray tube 4 and their primary windings 5 and 6 are adapted to receive electrical energy from the auto-transformer 1. The auto-transformer is provided with a pair of contactors '7 and 8 secured to a suitable insulated arm 9 so that movement or" the arm moves the contactors '7 and 8 in unison or the contactor 7 independently into contact with the various windings of the auto-transformer for varying the electrical energy supplied to the primary windings 5 and 6.

A conductor 10 extends from one end of the winding of the auto-transformer to one end of the primary winding 5. The circuit to this primary winding is then completed by a conductor 12 which extends from the opposite end of the primary winding 5 to the contactor 7. A conductor 13 extends from the opposite end of the inding of the auto-transformer to the primary winding 6 of transformer 2. A circuit to this primary winding is then completed by a conductor 14 which extends from the opposite end of the primary winding 6 to the contactor 8.

The primary windings 5 and 6 are thus connected in parallel with "each other and are each energized by the auto-transformer. A circuit to the primary winding 5 may be traced from one end of the winding of auto-transformer 1 through conductor 10, primary winding 5, conductor 12, and thence through contactor 7 to the Winding of auto -transformer 1. A circuit to the primary winding 6 may also be traced from the auto-transformer 1, through conductor 13, primary winding 6, conductor 14, and then through contactor 8 back to the winding of autotransformer 1.

The transformers 2 and 3 are provided with secondary windings 15 and 16 which are connected to the X-ray tube 4, for energizing the latter when a potential is applied to the primary windings and 6. A conductor 17 connects one end of the secondary winding with the anode of the tube while a conductor 18 inter-connects the two secondary windings 15 and 16 and is suitably grounded at 19. The filament of the X-ray tube receives energy for heating from a tertiary winding 20 carried by the secondary winding 16. A pair of conductors 22 and 23 extend from this tertiary winding 20 to the filament of the X-ray tube. A variable resistance 24 may be interposed in the conductor 22 for varying the current supplied to the X-ray tube if desired. When utilized with my apparatus it may be regulated once to give a predetermined minimum and maximum and need not be further disturbed or it may be dispensed with altogether as regulation of the current is made by my apparatus in a manner to be hereinafter described.

In moving the arm 9 over the windings of the auto-transformer and the contactors 7 and 8 in unison the potential across the electrodes of the X-ray tube 4 is maintained constant but the discharge current through the tube is varied. By moving the contactors for example to the left as shown in Fig. 1 the applied potential to the transformer 3 is decreased while the potential applied to the transformer 2 is increased. The secondaries of the two transformers being connected in series permits the aggregate of the output potential to thus remain constant.

As the potential applied to the transformer 2 is being increased it naturally follows that the discharge current is also increased due to the fact that the tube is supplied with heating currents through the tertiary winding 20 carried by the transformer 2.

When it is desired to maintain the discharge current supplied to the tube constant the contactors 7 and 8 are moved until a suitable milliammeter (not shown) records the desired discharge current. The contactor 8 is then permitted to remain in contact with the proper winding of the auto-transformer 1 while the arm 9 together with the contactor 7 is moved to vary the potential applied to the transformer 3. The potential applied to the transformer 3 being thus increased or decreased as desired and the potential applied to the transformer 2 remaining constant, it can readily be seen that the potential across the electrodes of the X-ray tube is consequently varied while the discharge current remains constant.

Referring now particularly to Figs. 2 and 3 I have shown a modification of my device wherein I utilize separate inductive devices in place of an auto-transformer. These inductive devices 25 and 26 are provided with primary windings 27 and 28 which are supplied with electrical energy from a suitable source of alternating commercial potential G. A pair of secondary windings 29 and 30 are carried by suitable shafts 32 and 33 and are journaled in suitable bearings (not shown) within the devices 25 and 26. These devices are similar in many respects to an induction motor and are herein illustrated as of the same appearance.

A pair of adjacent discs 34 and 35 are seowed to the respective shafts 32 and 33, and a suitable U-shaped bracket 36 is secured to one of these discs 34. This bracket is arranged to overlap a portion of the periphery of each of the discs and a lever 37 is pivotally secured to the unsecured flange of the U-shaped bracket. The control lever 37 at the pivot point is provided with a cam surface 38 which upon rotation of the control lever 37 about its pivot engages the disc 34 (see Fig. 4).

A brake band 39 surroimds suitable drums (not shown) secured to each of the respective shafts 32 and 33 to prevent rotation of these shafts and the secondary windings 29 and 30 due to the inductive relation of these windings with the primary windings 27 and 28 but allows rotation of these shafts and windings by the control handle 37. The secondary winding 29 is connected to the primary Winding 5 of high tension trans former 3 by means of the conductors 10 and 12 in the manner previously described. The secondary winding 30 is likewise connected by means of conductors l3 and 14 to the primary winding 6 of high. tension transformer 2.

It can thus be seen that in this modification I energize the primaries 5 and 6 of the hightension transformers 2 and 3 from individual inductive devices, the primaries of which receive energy from a common source of commercial potential, instead of a single auto-transformer but that in all other respects the circuit and structure is identical with the embodiment previously described.

Referring now more particularly to Fig. 3 I have shown the high tension transformers 2 and 3 encased in suitable housings 42 and 43 and disposed at each end of the X-ray tube 4. The X-ray tube 4 is in turn enclosed in a ray opaque housing 44, which engages the transformer housings 42 and 43, and a window 45 pervious to Y- rays is therein provided for the radiation of X- rays from the tube 4. This construction renders the entire structure compact and shock-proof. The inductive devices may be mounted in any position which enables ready access to the control lever 37 by the operator.

The operation of this modification is as follows: Assuming the operator desires to vary the discharge current but to maintain the potential between the electrodes of the X-ray tube 4 constant he will rotate the control handle 37 until the cam surface 38 contacts the disc 35. Both discs 34 and 35 are then engaged by the control handle 37 and the shafts 32 and 33, and secondary windings 29 and 30 are rotated by the control handle to vary the inductive relation of these secondary windings with the primary windings 27 and 28. This rotation of the inductive devices decreases the potential applied to one high potential transformer and increases the potential applied to the other transformer. This operation, due to the series connection of the secondary windings 15 and 16 allows the aggregate potential of both high tension transformers to remain the same thus maintaining the potential between the electrodes of the X-ray tube 4 constant, while the discharge current is varied by the increase or decrease of the applied potential to the transformer 2 carrying the tertiary winding 20 as before explained.

Assuming now it is desired to maintain the discharge current constant and to vary the potential between the electrodes of the X ray tube 4 the control handle is moved to a position in which it is parallel with the disc 35 thus disengaged from the disc 34. The control handle 37 may then be operated to rotate the shaft 33 and secondary winding 29 thus varying the potential applied to the transformer 3 without changing the potential applied to transformer 2. In this manner the potential between the electrodes of the X-ray tube 4 will be varied but the discharge current will remain constant due to the application of a constant potential to the primary winding 6 from the unaltered inductive device 26.

It thus becomes apparent to those skilled in the art that I have provided a compact unit adaptable to radiographic, fluoroscopic, or any other analogous purposes in which it is desirable to vary the discharge current in an X-ray tube while maintaining the potential between the electrodes constant or to vary the potential while maintaining the discharge current constant.

Although I have shown and described several embodiments of my invention I do not desire to be limited thereto as various other modifications of the same may be made without departing from the spirit and scope of the appended claims.

What is claimed is:

1. In an X-ray device the combination of an X-ray tube, a plurality of high tension transformers for supplying energy to said X-ray tube, a unitary controlling mechanism electrically connected to both of said transformers and operable to vary the energy supplied to one of said transformers independently of the other or both of said transformers simultaneously.

2. In an X-ray device the combination of an X-ray tube, a plurality of high tension transformers for supplying energy to said X-ray tube and means operable by a single lever for varying the energy supplied to one of said high tension transformers independently of the other or to both of said high tension transformers simultaneously.

3. In an X-ray device the combination of an X-ray tube, a plurality of high tension transformers provided with secondary windings connected in series with each other and with said X-ray tube for supplying energy thereto, and mechanism electrically connected to both of said transformers and operable to control the energy supplied to said transformers to cause the latter to maintain a constant potential across said X-ray tube and to vary the discharge current of said X-ray tube.

4. In an X-ray device the combination of an X-ray tube, of a plurality of high tension transformers provided with secondary windings connected in series with each other and with said X-ray tube for supplying energy thereto, and

controlling mechanism electrically connected to both of said transformers and operable to control the energy supplied to said transformers to cause the latter to vary the potential across said X-ray tube and to maintain the discharge current of said X-ray tube constant.

5. In an X-ray device the combination of an X-ray tube, a plurality of high tension transformers provided with secondary windings connected in series with each other and with said nism being operable from one position to another to maintain the discharge current constant while varying the potential across said X-ray tube.

6. In an X-ray device the combination of an X-ray tube, a plurality of high tension transformers provided with secondary windings connected in series with each other and with said X-ray tube for supplying energy thereto, and an auto-transformer for energizing both of said high tension transformers, said auto-transformer being provided with a movable control operable to simultaneously increase the energy supplied to one of said high-tension transformers while decreasing the energy supplied to the other of said high tension transformers, said control being operable to cause the potential supplied by both of said high-tension transformers to said X-ray tube to remain constant while varying the discharge current thereof or to vary the potential supplied by both of said high tension transformers to said X-ray tube and maintain the discharge current thereof constant.

7. In an X-ray device the combination of an X-ray tube, a plurality of high tension transformers provided with secondary windings connected in series with each other and with said X-ray tube, an auto-transformer connected in parallel with the primary windings of both of said high-tension transformers for energizing the latter, a tertiary winding carried by one of said high tension transformers for supplying energy for heating the filament of said X-ray tube, and a movable control arm carried by said auto transformer and operable to increase the potential supplied to one of said primary windings while decreasing the potential supplied to the other of said primary windings, said control arm being operable from one position to another to vary the discharge current supplied to said X- ray tube while maintaining the potential supplied thereto constant, and operable from one position to another position to vary the potential supplied to said X-ray tube and maintain the discharge current thereof constant.

8. In an X-ray device the combination of an X-ray tube, a plurality of high tension transformers provided with secondary windings connected in series with each other and with said X-ray tube for energizing the latter, a plurality of movable inductive devices for energizing said high tension transformers, one of said inductive devices being operable from one position to another independently of the other of said devices to vary the potential across said X-ray tube While maintaining the discharge current constant and both of said devices being simultaneously operable from one position to another to maintain the potential across said X-ray tube constant while varying the discharge current thereof.

9. In an X-ray device the combination of an X-ray tube, a plurality of high tension transformers provided with secondary windings and connected in series with each other and with said X-ray tube for supplying energy thereto, a plurality of inductive devices for energizing said high tension transformers, one of said devices being operable from one position to another independently of the other of said devices to vary the energy supplied to said high tension transformers and to simultaneously vary the potential across said X-ray tube While maintaining the discharge current of said tube constant, and both of said devices being simultaneously operable from one position to another to vary the energy supplied to said high tension transformers and to simultaneously vary the discharge current of said X-ray tube while maintaining the potential across said tube constant.

10. In an X-ray device the combination of an X-ray tube, a plurality of high tension transformers for energizing said X-ray tube, a plurality of inductive devices provided with primary and secondary windings for energizing said transformers, and means to vary the inductive relation between the primary and secondary windings of both of said devices simultaneously or one of said devices independently of the other of said devices.

11. In an X-ray device the combination of an X-ray tube, a plurality of high tension transformers for energizing said X-ray tube, a plurality of inductive devices provided with primary and secondary windings for supplying energy to said transformers, and means operable to vary the inductive relation between the primary and secondary windings of both of said inductive devices simultaneously and cause an increase in the energy supplied to one of said high tension transformers with an attendant decrease in the energy supplied to the other of said high tension transformers, and said means being operable to vary the inductive relation between the primary and secondary windings of one of said inductive devices independently of the other of said devices, to vary the energy supplied to one of said high tension transformers,

12. In an X-ray device the combination of an X-ray tube, a plurality of high tension transformers provided with primary and secondary windings for energizing said X-ray tube, a plurality of inductive devices provided with primary and secondary windings, the primary windings of said devices being connected in parallel to a source of commercial potential and the secondary windings of said devices being connected to the primary windings of said high tension transformers for energizingthe same, and means operable to vary the inductive relation between the primary and secondary windings of one of said inductive devices independently of the other of said devices to vary the energy supplied to one of said transformers, and said means being also operable to simultaneously vary the inductive relation between the primary and secondary windings of both of said inductive devices to cause a simultaneous variation in the energy supplied to both of said high tension transformers.

13. In an X-ray device the combination of an X-ray tube, a plurality of high tension transformers provided with secondary windings connected in series with each other and with said X-ray tube for supplying energy thereto, a plurality of inductive devices each provided with primary and secondary windings for energizing both of said high tension transformers, said devices being provided with a control for altering the inductive relation between the primary and secondary windings of said devices to simultaneously increase the energy supplied to one of said high tension transformers while decreasing the energy supplied to the other of said high tension 100 transformers and one of said devices being operable by said control independently of the other of said devices to vary the energy supplied to one of said transformers, said devices when simultaneously operated from one position to another 105,

maintaining the potential supplied by both of said high tension transformers to said X-ray tube constant while varying the discharge current thereof, and one of said devices when independently operated from one position to another vary- 17.0 ing the potential supplied by both of said high tension transformers to said X-ray tube while maintaining the discharge current thereof constant.

MONTFORD MORRISON. 

